DTS tracks seem to also be compressed (dynamic range compression, not bandwidth compression) which makes the quieter parts louder and raises the average levels of the entire presentation. That along with a really good bandwidth compression scheme (psychoacoustical model if you like $10 words) and some tweaking of the EQ give it an edge over Dolby Digital.
Dolby Digital is probably closer to the original track, but since when do viewers want to hear reality? Foley artists have to recreate what we recognize as footsteps and punches landing because we've been conditioned to listen for those outrageously inaccurate sounds. I haven't been in a fistfight for some time, but when I landed a punch back then, I don't remember it ever sounding like someone hitting a 12lb sirloin tip roast with a golf club.
Bren R.